so i've posted up my yonaka axle back forsale/trade and a guy with a greddy 4-2-1 1 piece header wants a trade.. i really want to go with the trade but i just dont know if the greddy 2.5in collector with a 2.5in test pipe will bolt right up onto my stock OE exhaust.. anyone?

 

does Stock Type R exhaust system have the same setup?

 

I know someone used a highend tri y header 2.5 collector with a 2.5 test pipe on his 1997 DX coupe with stock exhaust. He had to remove the cat tho.